A cooling apparatus includes: a water circuit; a ventilation heat exchanger that heats cooling water by heat exchange with air discharged to outside; a motor generator cooling unit; a motor bypass circuit that bypasses the motor generator cooling unit; and a flow rate control unit. When a temperature of the cooling water flowing between the ventilation heat exchanger and a motor flow rate controller is lower than or equal to a temperature of oil circulating inside the motor generator, the flow rate control unit increases a flow rate of the cooling water that flows from the ventilation heat exchanger into the motor bypass circuit.